What chords is he playing?

Hey all!

I am trying to learn NEEDTOBREATHE's "The Outsiders" and I am struggling to figure out the chords. I found a pretty good cover, but I cannot identify what chords he is using... Furthermore, it sounds like he is using standard tuned Banjo (G) with the 2nd string lowered in pitch 1 step or the equivalent of 2 frets to an A note. If anyone has any suggestions for me, I would appreciate it very much.

https://vimeo.com/140218586

Thank you for your time,

Michael